Water Budget Considerations Regarding Groundwater Extraction Targets in the Calera Aquifer Watershed, Mexico

Abstract

Groundwater extraction from the Calera Aquifer in the State of Zacatecas, Mexico, for irrigation, urban, and industrial uses has increased over recent decades to unsustainable levels. An annual, watershed-scale water budget analysis was conducted to identify alternative water conservation and water use scenarios, and to determine their effectiveness at reducing groundwater extraction. The scenario analysis showed that even with a 10% reduction in industrial and urban water use and a 50% reduction in irrigation water the annual groundwater deficit remains above 10 [10 6 m 3 /yr]. The political and socioeconomic impacts of such large reductions in water use are likely to be unacceptable. At best, a freezing of industrial and urban water use at the level of year 2010 and a 50% reduction in irrigation water use can be hoped for, which leads to an annual groundwater deficit of about 20 [10 6 m 3 /yr]. This is a great improvement over the 75 [10 6 m 3 /yr] groundwater deficit of year 2010, and could potentially be adopted as a target deficit that qualifies as sustainable utilization of groundwater resources. To achieve a 50% reduction in irrigation water use will likely involve a combination of higher irrigation efficiencies,